562 
J. BRONTE GATENBY. 
altere que les mitochondries environnantes par les solvants 
des graisses ; les mitochondries resistent parfaitement a ceux- 
ci, et j’ai note qu’un spermatozoide d’Arion traite apres disso- 
ciation par Talcool et le chloroforme et colore par la 
mSthode de Mallory montre les deux cordons mitochondriaux 
se colorant par la fuchsine acide avec energie.” 
Technique. 
All the earlier observers hardly without exception found 
that Flemming’s strong formula gave the best results of any 
fixatives at their disposal. 
Murray ( 8 ) got good results with Perenyi. Flemming’s- 
unmodified formula I consider out of date and worthless fora 
study of the cytoplasm. Its fault lies in the presence of 
acetic acid, a reagent which should never be used for work 
on the plasma. As I explained in my last paper, a modifica- 
tion, which I found best, was to cut out all the acetic acid. 
Meves, in his great cytological work, used a Flemming of 
this sort : 15 c.c. of chromic acid of 1 per cent., containing 
NaCl of 1 per cent., and 3 to 4 c.c. of osmic of 2 per cent.> 
with three or four drops of acetic acid. Benda used a 
Flemming with only three to six drops of acetic acid to 15 c.c. 
chromic and 4 c.c. osmic. I feel sure that it is dangerous to 
try to temporise between two fixing solutions, as nuclear and 
cytoplasmic, by simply cutting down the acetic. These 
observers retain just enough acetic acid to distort the mito- 
chondria, and the small improvement in the appearance of the 
nuclei and in the penetrative power is quite outweighed by 
this glaring fault. As I have mentioned before, the discussion 
as to whether the mitochondria are rods or granules may be 
largely a question of acetic acid and such-like injurious re- 
agents. 
Any fixative in general use will give a passable fixation of 
the nucleus, but work on the cytoplasm is a very different 
story. In the cytoplasm w.e have no bodies bounded by close 
membranes, but structures which can be, and always are,. 
